1. Field of the Invention
The present invention relates to a method for forming contact holes in a semiconductor device, and more particularly to a method for forming contact holes having a critical dimension in the fabrication of a highly integrated semiconductor device.
2. Description of the Prior Art
Generally, semiconductor devices have a reduced unit cell area as the integration degree increases. Due to such a reduced unit cell, the space between adjacent conductors is also reduced. The size of contacts adapted to connect lower and upper conductors may also be reduced.
To this end, it is required to provide a technique by which an upper conductor is in contact with a lower conductor such as a silicon substrate while maintaining an insulation from a narrow intermediate conductor.